Impulse starter



`lune 24, 1924. 1,498,586

J. R. STARK IMPULSE STARTER June 24., 1924. '1,498,586

J. R. STARK IMPULSE STARTER Filed Oct. 6, 1920 2 Sheets-Sheet. 2

Patented June 24, 1924.

UNITED STATES PATENT CFFICE.

J CHN ROY- STARK, OF RACINE, .WISCONSIN, ASSIGNOR TO WEBSTER ELECTRIC COM- IPANY, OF RACINE, WISCONSIN, A'CORPORATIDN 0F WISCONSIN.

IMPULsE STARTER.

Application mea oetober'e, 1920. serial No. 415,206.

To all whom z't may, concern.'

\Be it known that I, JOHN ROY STARK, a citizen of the United States, and resident of Racine, in the county of Racine and State of Wisconsin, have linvented a certain new and useful Improvement in Impulse Starters, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part, of this specification.

y invention is concerned with the provision of a so-called impulse starter capable of being used in connection with an internal combustion engine ignition magneto, it -being the function of the impulse starter prior to the creation of each ignition spark, at the moment of starting, and at low engine speeds, to cause the armature or rotor of the magneto to be locked against movement by the engine, released, and then moved rapidly at a speed independent of engine speed through a definite angle under the tension of a spring in which energy vhas been stored by the engine during the time interval that the said armature or rotor is-lockedagainst movement by the engine. i

Those features of construction vwhich characterize mypresent invention are particularly applicable to impulse starters embodying the invention disclosed in Patent No. 1,246,312, granted to Nero and Pontus Ostenberg, on November' 13, 1917. In the accompanying'drawings illustrating my invention- Figure 1 is a front elevational viewi illustrating the impulse starter of my invention applied to an ignition magneto.

igure 2 is a vertical sectional view taken on the line 2-2 of Figure 1, and looking in the direction indicated by the arrows.

Figure 3 is a vertical sectional view taken on the line 3 3 of Figure 2,- and looking in thev direction indicated by the arrows.

Figure 4 `is a view similar to Figure 3, illustrating the several parts of the impulse starter -in the positions occupied thereby, im` mediately prior to the releasal of one of the locking pawls from the abutment afforded by .the fixed impulseI starter housing.

v'Figure 5 is a vertical sectional View taken 'on line 5 5 of Figur 2 and looking in the direction indicated by the arrows.

`Figure G is' an/ isolated view in perspective ,.of-.thekixed housing. v

-illigure 7 is an isolated view in perspective villustrated a of the driven element of the impulse starter, and

Figure '3 is an isolated view in perspective of the driving member of the impulse starter.

Similar characters of reference refer to similar parts throughoutthe several views.

i Referring first to Figure 1, at 10 I have rotary ignition magneto, which, so far as my invention is concerned, may be of any suitable type. The magneto comprises the usual armature or rotor shaft illustrated at l1.

The several parts of the impulse starter are enclosed within a fixed housing 12 illustrated in perspective in Figure 6. This housing, which is formed in one piece, comprises the wall 12a, which is provided with annular flange 12b. Wall 12a is provided with a central aperture 12c for the reception of armature shaft 11, and with 'a plurality of openings 12d for the reception of the screws 13-13, wherewith the housing 12 is rigidly attached to the magneto frame, as shown in Figures 1 and 2. Openings 121 are preferably counterbored so that the heads of 'screws 13-13 lie flush with the inner surface of wall 12a.' Attention is directed to the fact Athat wall 12a and liange 12b are conformed to provide an offset recess 12e, one of the inclined end walls of which, indicated at 12T, constitutes an abutment for the locking pawls presently to be described. When housing 12 is secured to the magneto frame as 'illustrated in Figure 2, the said housing provides a chamber open only on that side of the housing away from the magneto frame.

The driving element of the impulse starter is indicated at 14 and is shown in isolated perspective in Figure 8. This driving member is formed in one piece, and comprises the wall 14a provided with an annular flange' 14", the outer diameter of which is substantially equal to the inner diameter of the flange 12bof fixed housing 12, so that iange 14b may fit snugly within iiange 12". for rotary movement therein. Vall 14a is provided with a central aperture 14 and is also provided with a pair of driving lugs 14d, which are adapted 'to co-operate in a well-known manner with means driven by the engine with which the magneto is associated. Cut in the liange 14b are the oppositely located notches 14e, -the said notches being of equal and considerable depth, each notch in length representingapproximately '75 degrees on the annular flange 14". It will be noted that the metal of the flange 14 is beveledat 14-14. As will presently appear, the beveled surfaces 14f-14f serve as Wedges to disengage the locking pawls from the abutment 12 of the fixed housing 12. Flange 14b is furthermore provided with an aperture 14g to facilitate attachment of the driving member to'a clock spring as will presently be explained.

The driven element of the impulse starter is designated at 15 and is illustrated in isolated perspective in Figure 7. driven member comprises the disc 15a having a central opening 15b and is provided with a suitable key slot so that the said driven member may be keyed upon the armature shaft as is shown in Figure 2.A It will be noted that the thickness of disc 15 is less than half the depth of the notches 14e of the driving member and that disc 15a is provided with lugs 15-15, whichv extend into the notches 14e when the parts Vare assembled as shown in Figure 2. Disc 15a has formed integral therewith a hollow, cylindrical boss 15d, this boss being disposed concentric with the aperture 15b and being provided with a slot 15 for the reception of one end of the clock spring. Projecting from that face of disc 15a opposite the boss 15d are a pair of diametrically opposite pins 15 f, which serve to carry the locking pawls.

The clock spring is illustrated at 16. This spring lies around boss 15d with one end thereof engaging in slot 15e and the other end thereof engaging in the opening 14g ofl the driving member. vIt should be noted that the flange 14" is milled on its outer surface at a point adjacent the aperture 141g so that the outer end of spring 16 will not project beyond the outerv cylindrical surface of flange 14". f Prior to the assembly of the driving and driven members, the spring 16 is given a certain amount of initial tension, so that the spring normally tends to urge the driven member in the direction of armature rotation, thereby holding the lugs 15!- 15c in those ends of the driving member notches omposite the beveled surfaces 14E,

formed integral With the driven member and bounding the central aperture l15b thereof. The shape of'each of the pawls is such that Whenever the long, trailing end of one of the pawls lies in engagement with The saidy flange 15g, the nose of the pawl is projected through one of the notches 14e of the driving member.

When the parts are assembled as shown in Figure 2, the boss 15d of the driven member lies in the opening 14 of the driving member and the spring 16 lies in the annular space between the disc 15l and the wall 14". Displacement of the pawls from the pins 15f--15t is prevented by the wall 12 of the fixed housing 12. In order to prevent the ingress of dust, a drawn metal cup 18 is fitted into the Vhollow boss 15d of the driven.

member. 'This cup is provided -with a central aperture to receive the end of the armature shaft and is held in position by a nut 19. It will be notedthat the cup 1S is provided With an annular flange 18a, which overlaps the space between the boss 15d and the Wall 14a of the driving member, the said Wall 14% preferably being provided with an annular seat to receive said flange, asis clearly shown 1n Figure 2.

In Figures 1, 3 and 4, the arrows indicate i the direction in which the driving member \00 is rotated by engine driven means co-oper* ating with lugs 14d-14d. New let us assume that the driving member is being rotated at sured because the heavy, trailing end of the awl gravitates to a` position against the ange 15g', and thus forces the nose of the pawl out through the adjacent notch 14e. After the nose'of one of the pawls engages abutment 12t as shown in Figure/3, further movement of the driving member is taken ./up by the spring 16 until one of the beveled surfaces 14t of the driving member flange 141? engages the nose of the pawl as shown in Figure 4, and disengages the pawl from the abutment. As soon as thisdisengagement is effected, the spring serves rapidly to rotate the driven member ahead of the driving member until such movement is stopped by engagement of the lugs 15C--15c with the driving member flange 14". So long as the driving member continues to rotate at slow speed, the operation just described occurs twice during each revolution of the driving member. The intermittent rapid rotary movements which are thus imparted to the armature result in the. generation of effective ignition currents in a man ner, and for the reasons, well known to persons familiar with the art to which my invention relates. v

When the driving and driven members 1 I claim 1s new and are rotated at high speed, the'heavy trailing ends of the pawls4 17l7 are -held out against the flange 14h of the driving member by centrifugal force. In this case, the pawls do not` engage the abutment of 'the fixed housing and continuous rotary movement is imparted to the driven member from the driving member through the clock spring.

Having thusdescribed my invention, what A desire to secure by Letters Patent is:`

1. An impulse starter comprising a housing consisting of a centrally apertured Wall, provided with an annular' flange, said housing adapted to be fixed to a magneto frame with the armature shaft of the magneto ex'- tending'freely through the aforesaid aper-` tured wall, said wall and flange being conformed to provide an offset recess, one end wall of which constitutesan abutment, driving and driven members disposed in said housing, springmeans interposed between said driving and driven members, a pawl carried by the driven member adapted to engage saidr abutment, and lock the driven member to the housing, when the driven 4member is rotated at low speed and means on the driving member for disengaging the pawl from the abutment, said pawl being centrifugally actuated to an inoperative position when the driving member is rotated at high speed. c

2. An impulse starter comprising a housing consisting of a centrally apertur'edwall, provided with an annular flange, said housing adapted to be fixed to a/magneto frame with the armature shaft of the magneto eX- tending freely through the aforesaid aper-y tured Wall, said housing provided withan offset recess one end wall of which constitutes an abutment, driving and driven members disposed in said housing, the driven member adapted to be fixed to the armature shaft, spring means interposed between the driving and driven members, a pawl carried by the driven member, said pawl being gravity operated to engage said abutment when the driven member rotates at low speed, and centrifugally operated to aninoperative position when the driven member rotates at highspeed, together withmeans for disengaging the pawl from the abutment when, after the engagement of the pawl and abutment, as aforesaid, the driving member has been given a definite amount of rotary movement independently of the driven member.V

3. In an impulse starter, a substantially circular drivenfmember provided with a peripheral lug, a driving member comprising an annular flange adapted to embrace the 'driven member, a notch in said flange adapted to receive the peripherallug, the depth of the notch being greater than the thickness driving member flange as aforesaid, the\- flange of the driving member being adapted to disengage the pawl from the abutment when the driving member hasbeen given a definite amount of movement independently of the driven member.

4. In an impulse starter, `a substantially circular driven member provided withfa peripheral lug, a driving member comprising an annularfiange adaptedto embrace the Y driven member, a notch in said flange adapted to receive the peripheral lug, the depth of the notch being greater than the thickness of the lug, spring means interposed between the driving and driven members, a pawl car ried by the driven member, said pawl being gravity actuated to project the nose thereof through the notch in the flange of the driv` ing member when the driven member is slowly revolved, and centrifugally actuated to retract the nose of the pawl when the driven member is rotated at high speed, together with a fixed housing in which the driving and driven members are disposed, said housing being provided with a fixed abutment adapted to be engaged by. the nose of the pawl when the latter' projects through annular flange adapted to embrace the Vdriven member, a notch in said flange, arranged to receive said lug, said notch being deeper than said lug so as to provide a dprojecting portion, spring means interpose between the driving and driven members, a pawl carried by the driven member, said pawl being gravity actuated to project the nose thereof through said notch in said projecting portion when the driven member is slowly revolved, and centrifugally actuated to hold the nose of the pawl retracted when the driven member is'rotated at high speed, together with a fixed abutment adapted-to be engaged by the nose of the pawl when the given latter projects through the notch inV the driving member flange, said ange being adapted to disengage the lpavvl from the abutment when the driving member has been a definite amount of' rotary movement independently of' the driven member. 6. An impulse stai-ter,comprising allonsing and driving and driven members disposed in the houfsing for rotary movement therein," said housing beingufixed to the end plate of the magneto frame and the driven member to the armature shaft of a magneto, a boss on that side of the driven member nextadjacent the driving member, a spring disposed between the driving ,and driven members and attached to each,"a liange on the driving member adapted to embrace the` driven member, a notch in said flange, a pawl carried by the driven member, and provided with a nose adapted to project through said notch, an abutment carried by the housing adapted to be engaged by the nose of the pawl When `the latter projects through said notch, the flange of thel driving member beingadapted to disengage the pawl from said abutment when the driving member has been given a definite amount of rotary movement independently of the driven member'.

-7. An impulse starter comprising a fixed housing secured to the end plate of' a magneto, driving and driven members disposed in said housing, said driven memberadapted to be secured to the 'armature shaft of the magneto, spring means interposed between the driving and. driven members and atthe latter projects through i said notch, said driving member flange serving to disengage the pawl from the abut.

mentl when the driving member has been given a definite amount of rotary movement independently of the driven member.

8. In an impulse starter, a housing member fixed to the magneto frame, an annular iange projecting fromsaid housing, a driving member' having an annular flange in close engagement wvith said housing flange, said housing member and said driving members serving to form a complete housing, a driven member Within said housing, resilient means joining said driven member to said driving member, a fixed abutment on the annular flange of said housing, a paWl carried by said driven member and arranged to engage said abutment, and means on said driving when said ydriving member has moved a definite angular distance in ,relation to said driven member.

PRESTON Gr. CREW, E. M. FORD.

member for releasing said pawl '65 In Witness whereof, I hereunto subscribe lmy name this 28th day of Sept., 1920. 

